Submarine signaling apparatus



J. T. BEECHLYN SUBMARINE SIGNALING APPARATUS mm 9 u 5 1 e n u J 2 Sheets-Sheet 1 Filed Feb. 28, 1944 INVENTOR. JOHN T. BEE CHLYN J1me 194$ J. T. BEECHLYN SUBMARINE SIGNALING APPARATUS zmsm? 2 Sheets-Sheet 2 Filed Feb. 28, 1944 FIG.6

FIGB

INVENTOR.

JOHN T. BE ECHLYN Patented June 15, 1948 STAT PATENT QFFECE SUBMARINE SIGNALING APPARATUS Application February 28, 19414, Serial No. 524,989

15 Claims. (Cl. 177-386) The present invention relates to a device for sending and receiving compressional waves and more particularly to a magnetostrictive device adapted to be used in a fluid and liquid medium for the transmission of compressional waves in sub-audible, audible or super-audible range. The invention is particularly applicable to submarine signaling both for transmission and for reception and may therefore be called a transducer which is commonly applied to devices capable of translating compressional energy to electrical energy or vice versa. The device may also be used as a transceiver for transmitting and receiving compresisonal waves. The design of magnetostrictive devices'for the transmission and reception of compressional waves has brought into common use certain types of these devices which operate successfully for the purposes to which they are applied. Among the commonly used devices are so-called'magnetostrictive oscillators built up of laminations forming blocks through which coils are threaded in a number of ways; most of these are resdnant at a desired frequency. Another known type of magnetostrictlve oscillator or transceiver is one in which one or more tubes are surrounded by coils producing longitudinal varying flux which creates corresponding mechanical motion. A plate or sound radiator at the end of the tube provides a coupling with a propagating medium.

The present invention diflers from the art briefly described above and from other devices in a number of features which provide definite advantages under many circumstances where the present device is to be used. The arrangement according-to the present invention may be built up into almost any desired form of radiating surface, itself occupying substantially a rectangular casing with desired elongated dimensions, or a portion to its size, and can easily be used and manipulated in the water in connection with overboard devices and floating devices or devices which may be fixed with anchorage in definitely chosen spots.

The apparatus is also adaptable for use with a parabolic or hyperbolic reflector for directive transmission and reception in a beam or in a fan shaped plane and for this purpose the sound characteristic pattern is made up of arrangements of groups of tubes covering the space over which radiation is desired to be provided. As regards the acoustical properties and advantages of the present construction, it is desirable to point out that resonance of the structure is produced for a motion of the structure against which no direct radiation damping occurs. In this respect a group of independently vibrating longitudinal sections is used in which resonance may be established for the longitudinal length, whereas the actual radiationinto the medium occurs through the transverse expansion and contraction of the tubes.

Further the design of the present invention is particularly adaptable for providing either a sharply tuned or broadly tuned system, since the device has two modes of resonance, the longitudinal and the transverse which are coupled inherently in the tubes of the device. These and other features will be more fully described in connection with the specification annexed hereto describing the-invention as illustrated by the drawings in which Fig. 1 shows an elevation of the invention with parts in fragmentary section. Fig. 2 shows a section taken on the line 2-2 of Fig. 1. Fig. 3 shows a broken section through a modification of the invention shown in Fig. 1. Fig. 4 shows a cross section through a further modification of the invention corresponding to a transverse cut of the section of Fig. 3. Fig. 5 shows a broken section with parts in fragmentary view of a still further modification of the invention shown in Fig. 1. Fig. 6 shows a section taken substantially on the line 6-- of Fig. 1. Fig. 7 shows a section taken substantially on the line 1-1 of Fig. 5, and Fig. 8 shows a device in accordance with Figs. 4 or 5 used with a reflector. Fig. 9 shows a set of resonance curves relating to the operational characteristic of the apparatus.

In the invention shown in Figs. 1, 2, and 6, the invention comprises mainly a group of tubes I, 3; d, 5, 8 and l which are made of magnetostrictive material through which is threaded one or more electrical conducting wires 2, longitudinally the length of the tube as indicated in Fig. 1. This wire may be threaded down through one tube and up through the next tube and passing in this manner through all of the tubes. While a single turn is shown in Fig. l, the conductor 2 as indicated in Fig. 2 may comprise a group of wires and also the manner of threading the wires may be in accordance with any desired arrangement. For instance, the wires may be looped through any par of tubes as shown in Fig. 3, or may be looped through some pairsof tubes first before entering the other tubes. The main purpose of thearrangement of the conductors is to establish a magnetic flux in the magnetostrictive tube members i, 3, 4, 5, 8, I, which circulates around the circumference or wall of the tube. The tubes are opened at each end as indicated in Fig. 1 and are set in and sealed at both ends in retaining plates 8 and 8 forming parts of enclosing chambers from which the liquid propagating medium is excluded. The retaining plates 8 and 9 at each end form end supports which are supported by the external casing I0, which is provided with end walls I I and I2 and side walls l3 and I4. These walls are perforated by holes I'B-lii, et cetera, to permit the propa ating medium or liquid, as for instance water, if the device is used for signalling in water, to enterinto the chamber formed within the casing for the purpose of filling the chamber-and surrounding the tubes with the propagating or radiating medium but no liquid enters into the tubes. The tubes I, 3 et cetera, may be made of the same or diilerent diameters and may be divided into independent vibrating sections by projecting flanges ll, i8, i9 and .20. These flanges are formed by any suitable means which bend out the walls of the tubes forming a narrow U-shaped section as viewed in Fig. 1. This type of joint between any two sections of the tube, as for instance, sections 2i and 22 permit the sections to vibrate longitudinally unimpeded, without any substantial reaction from one section to the other. By establishing the various sections of the tubes at the same lengths, the tubes will be made substantially resonant at the same frequency in a. longitudinal direction. This resonance is substantially independent of the diameter of the tube. In the arrangement indicated in Fig. 1, the magnetic flux circulates through the walls of the tube in directions concentric with the axis of the tube. As is well known magnetostrictive tubes made of nickel undergo an increase in flux in response to a contractive force and vice versa an increase in flux produces a contractive action which tends to contract the tube so that when the flux increases the circumference of the tube decreases. Whether this is a primary or a. secondary eflect has not been scientifically established but with the alternate expansion and contraction of the diameter of the tubes due to the alternating flux in the tubes a corresponding longitudinal vibration takes place in the tube section and if this longitudinal Vibration is established for the iongitudinal resonance of the tube, then the mechanical forces in the tube act at resonance to enhance the lateral contraction and expansion amplitude of the tube itself. The longitudinal resonance of the tube is unimpeded from the point of view no radiation occurs because of this motion and therefore no water load is impressed upon the tube merely by means of this longitudinal vibration. The lateral expansion and contraction of the tube acts against the propagating medium to impart vibrations to the medium and this furnishes the comparatively large water load with small linear amplitude as compared to the larger longitudinal linear amplitude of the sections of the tubes. The radiation of each tube section will be in the same phase when the tubes are made substantially alike, and therefore a substantially plane wave may be produced when from leaking out into the end chambers and 24 into which the conducting wires extend where electrical terminals and joints may be made and assembled. The end chambers 23 and 24 are formed by the plates 8 and 9 over'which is placed cover members 25 and 24 which are sealed to the end plates by suitable gaskets or flanges 21 and 28 which are clamped .between flanges 2! and 30 of the covers by means of the bolts ll et cetera for the flange 28 and 32, 32 et cetera for the flange .30. The cover member 25 may have a cable fltting 33 through which the cable 34 is sealed. This construction will prevent the liquid from entering into the inside of the tubes and also acting on the electrical conductors. It is very necessary that the insides of the tubes be kept free from external liquid in order to avoid damping of the tubes if the liquid were within the tubes.

As indicated in Fig. 2, if radiation is desired only through one side of the casing, the other side may be lined with an acoustic reflecting layer 35 which may be cork with a plastic binder as for instance the material called corprene" orany othersuitable sound reflector may be used. The spacing 'of the tubes from the reflecting wall may be such as to provide the proper reflecting phase between the reflected waves and the propagated waves so as to build up the radiation am plitude. If the tubes are spaced substantially a quarter of a wave length from the reflecting wall, then the reflected wave from the wall will be substantially in phase with the wave radiated from the tube in the direction normal to the reflecting wall. In the arrangement just described, the tube lengths 2| and 22 may be given a longitudinal resonance for the wave to be propagated or received while the lateral hoop resonance of the tube is made higher than that-at which the device is intended to operate.

In the description of some ofthe other arrangement-s, it will be pointed out how the longitudinal and lateral or hoop resonance maybe established at the same value and how this interaction of the two resonances may be used to establish and broaden the resonance curve which is particularly useful for the device when it is used as a receiver of noise or broad band signals.

The arrangement shown in Fig. 3 may be used with a single pair of tubes or with groups of tubes forming two lines one of each line forming a pair;- The arrangement shown in Fig. 3 also differs however from that of Fig. 1 in its structural effect. In this case the tubes 40 and M may be substantially larger than the corresponding ones of Fig. 1 or they may have a large number of longitudinal sections separated by the connecting flanges 42 43, et cetera. The top end of the tubes may be supported in a frame 44 in which the ends of the tubes are hermetically sealed. The frame 44 may be provided with an outwardly extending flange 45 which is clamped between two collars or rings 46 and 41, the ring or collar 41 being the end element of a cover or casing 48 enclosing the end of the device. The

flanges 46 and 41 .are held together by means of the screws 49 which thread through the flanges 46 and 41 and pull the flange 45 against the face of the flange 46 between which elements a clamping ring 50 is positioned to effect a watertight seal. A conductor 5| enters through a packing gland 52 at the top of the casing 48 and this conductor 5| carries the conducting wires 58 and 54 which are the terminals of the coil 55 which threads longitudinally down through one tube M and up through the other tube 42. The lower end of the tubes M and 42 is sealed in a head 56 which forms one wall of a chamber 51 in which the conducting coils pass going from one tube to the other tube. The current circulating in the Wires 53 and 54 provides a circulatory flux concentric with the axis of the tubes All and M and the magnetostrictive effect of the tubes is the same as that described in connection with Fig. 1 namely the alternating flux expanding and contracting the tubes laterally provide a lateral radiation of the compressional waves. The longitudinal lengths of the section may here also be designed to provide a longitudinal resonance at the frequency at which the devices will operate. The tubes Ml and M may be surrounded with a shell 58 which may be welded-to the inside of the flange 66. This shell may have perforations so as to permit the entrance of the propagating liquid or fluid medium.

In Fig. 4 a section is shown through a modification in which a number of tubes is arranged uniformly in a circular or polygon shape. Each of these tubes 60, 8!, 62, 63, 64 and 55 may be retained and supported in a manner similar to that shown in Figs. 1 and 3, and the coil 66 may be threaded in and out of the tubes in the same manner as that shown in Figs. 1 and 3. The threading of the coil in the tube may be in series or series parallel or in any desired arrangement. The tubes of Fig. 4, like those of Figs. 1 and 3,

are sealed against fluids and liquids, but are im-' mersed in the chamber 61 which may be filled with the propagating medium and which is protected by means of the shell 68. The operation of the device according to Fig. 4 is similar to that described in connection with Figs. 1 and 3.

In the arrangement shown in Figs. 5 and 8 the construction is such as to send the flux lengthwise in the magnetostrictive tube. Here the magnetostrictive tube ill is of the same type as described in the previous modifications with sections of the tube ll, 12 joined by coupling flanges '33 which permit each tube to vibrate independently both in the longitudinal and transverse directlon.- These tubes may be of such a diameter that they have a so-called hoop resonance at the same resonant point as the longitudinal resonance-of the sections. The tube is supported at its ends in top-and bottom heads 14 and 15, respectively. -Within the magentostrictive tube there ispositioned an assembly comprising an inner laminated core 16 surrounded by a coil Tl wound on an insulating form 18 which may be of Bakelite or other suitable material. The form flts closely to the core and the coil carries the alternating current for vibrating the tube or acts to pick up the currents received by the system, depending upon what use the device is put to, whether a transmitter or receiver. Surrounding the coil and fltting close to the coil form is a shell 19 which may be concentric with the inner core and the coil and which is a permanent magnetmade of such material as alnico or other highly permanent magnetizable metal. As indicated in Fig. '7, this shell I9 is split as at 80 to prevent the circulation of eddy currents. A collar BI is placed around the top of the form 18 0 which it fits snugly and about this collar fits the sleeve 82 which has an internal recess 08 holding the end of the tube 10. The sleeve 82 is recessed on the outside to receive the tube or shell 84 of copper or other conductive material for purposes of confining the alternating magnetic flux within the shell of the tube. The top of the device is made watertight by means of the packing gland 85 which is clamped by means of the screws 86 to the ends of the sleeve 832. The cable 8'! is led through the packing gland and connects by means of the wires 88 and 88 to the coil H.

In the arrangement as described, the coil l1 carries the alternating flux at the frequency at which the vibrations in the tubes are to be produced. Normally with no current flowing in'the -coil l! the return magnetic path for the permanent magnet is divided, part flowing through the magnetostrictive tube and the other part flowing through the laminated central core. When alternating current flows through the coil, the direct current flux through the laminated core,ls alternately opposed and aided by the alternating current flowing through the coil. This action will unbalance th portion of the constant flux flowing through the magnetostrictive member, and the reaction of this and of the alternating flux through the laminated core will vary the flux through the magnetostrictive member in accordance with the variation of current flow through the coil. The outside tube 84 which provides in effect a short-circuited secondary coil acts through the eddy currents circulating in it to confine the magnetic flux emanating from the permanent magnet to flow through the magnetostrictive tube rather than to spread out in the space beyond the wall of the tube. The variation in longitudinal flux in the magnetostrictive tube will produce a longitudinal vibration and a corresponding transverse vibration in the form of a lateral expansion and contraction of the tube. The diameter of the magnetostrictive tube may be so chosen that its hoop resonance or the resonance in the motion of the lateral expansion or contraction is of the same frequency as the longitudinal resonance between coupling flange sections of the tube.

In Fig. 9 a set of curves is shown illustrating the combination of resonance of the system due to the longitudinal and transverse resonance.

peaks. The curve 90 may be the curve corresponding to the longitudinal resonance of the tube sections while the curve 9| may correspond to the hoop or lateral resonance of the tube sections. These resonance peaks may coincide with the axis 92 or, if desired, they may be separated by a small frequency difference. The coupling of these two resonance systems produces a broadened resonance curve asillustrated by 93 in which there are two peaks A and B, one corresponding to longitudinal resonance and the other corresponding to transverse resonance. The tuning in this case has a band width substantially between vertical lines C and D whereas the individual resonance elements have a much narrower band width. For reception purposes a resonance system is obtainable which has a considerable breadth for tuning over the receiving range. The device of this nature ma be designed for reception over a broad supersonic band or over a narrower sonic band, depending upon the dimensions and couplings in the system. In a closely coupled structure where most of the energy in the two resonant systems are interchanged with each other, the peaks A and B are more. widely sepanon-r:

therefore the system may be broadly tuned. that is. tuned over a wide band.

In the arrangement shown in Fig. 8 a device 8 compared to the portions of the tube coupled thereby permitting the portions of the tube sepsuch as disclosed'in Fig. 4, or, in fact, some of the other figures, may be used. Here the tube 08 may be set at the focus of a parabola or of the corresponding point oi a rectangular hyperbola or any other reflecting body such as the reflector 85. -The reflector may, if desired, be turned about the tube 88 as the axisboth for directively sending and for reception.

.In the constructions which have been described it will be noted that the tubesare substantially freely supported inasmuch as the end coupling sections are positioned substantially just beyond the place of support of the tube. This is clearly indicated in Figs. 1, 3 and 5. I

In Fig. 5 the lower support end is similar in structuretothe top support end. The support for the tube III is in the section just beyond the,

coupling flange section 86 leaving the tube 12 substantially free for longitudinal and transverse vibrations. The external tube 04, as indicated in Fig. 5, flts around a shouldered recess 81 formed in the end cap 8L The inner side of the end cap 8| has also a recessed shoulder 98 in which the end of the tube II is supported. The inner portion of the end structure is similar to that at the top of the structure with the laminated core 16 extending down to the base of the cap 88 and the bottom of the form II on which the coil 11 is wound extending also down to the base of the cap 98.

' Having now described my invention, I claim:

1. Means for sending or receiving compres- I sional waves comprising a'magnetostrictive tube having spaced flexible coupling sections permitting the'portions of the tube separated by the coupling means to vibrate substantially freely andindependentl'y of one another, means for impressing varying magnetic flux in the'tube to produce longitudinal vibrations thereof or reacting to variations of magnetic flux for reception and a compressional wave propagating medium surrounding the outer surface of the tube.

2. Means for sending or receiving compressional waves comprising a magnetostrictive tube having spaced flexible coupling sections permitting the portions of the tube separated by the coupling means to vibrate substantially freely and independently of one another, coil means for impressing varying magnetic flux or picking up currents induced by varying electric flux in said tube, and a compressional wave propagating medium surrounding the outer surface of the tube.

3. Means for "sending or receiving compressional waves comprising 9. magnetostrictive tube arated by the coupling means to vibrate substantially freely and independently of one another, comprising a flanged portion of the wall at an angle with the wall of the tube in chosen transverse directions and coil means operatively associated with the tube for interchanging electrical and mechanical energy in the tube.

5. Means for sending or receiving compres-' sional waves comprising a magnetostrictive tube having spaced flexible coupling sections short compared to the portions of the tube coupled thereby permitting the portions of the tube separatedby the coupling means to vibrate substantially freely and independently of one another, comprising a flanged portion of the wall at an angle with the wall of the'tube in chosen transverse directions and a coil linking the wall of the tube for interchanging electrical and mechanical energy in the tube.

6. Means for sending or receiving compressional waves comprising a magnetostrictive tube having spaced flexible coupling sections short compared to the portions of the tube coupled thereby permitting the portions of the tube separated by the coupling means to vibrate substantially freely and independently of one another,"

comprising a flanged portion of the wall at an angle with the wall of the tube in chosen transverse directions and a coil linking the wall of the tube in a longitudinal direction for interchanging electrical and mechanical energy in the tube.

7. Means for sending or receiving compressional waves comprising a magnetostrictive tube having. spaced flexible coupling sections short having spaced flexible coupling sections short compared to the portions of the tube coupled thereby permitting the portions of the tube sep arated by the coupling means to vibrate substantially freely and independently of one another, comprising a flanged portion of the wall at an angle with the wall of the tube in chosen transverse directions said sections being spaced apart on the tube to provide substantially the same resonance frequency for more than one section of the tube, and coil means operatively associated with the tube for interchanging electrical and mechanical energy in the tube.

8. Means for sending or receiving compressional waves comprising a plurality of magnetostrictive tubes spaced apart parallel to one another, said magnetostrictive tubes being divided in sections by means of short flexible coupling sections comprising an outwardly flanged portion of the walls of the tube at an angle therewith, end supporting elements for the tubes and conductor means threading through the tubes for interchanging electrical and mechanical energy between the tubes and the conductor means.

9. Means for sending and receiving compressional waves comprising a plurality of magnetostrictive tubes spaced parallelly from one another and divided in sections of substantially the same length, said sections being formed by short flexible coupling Joints in said tubes making said sections substantially independent of each other and electrical conducting means threading through said tubes for linking current in the conductor with flux in the tubes for interchanging electrical and mechanical energy.

10. Means for sending or receiving compressional waves comprising a plurality of magnetostrictive tubes arranged parallel with each other flexible coupling section means dividing said magnetostrictive tubes into sections independent of one another forming independent resonating elements, said coupling sections being short compared to the lengths of tubes coupled together, a pair of end plates one at each end of said tubes in which said tubes are positioned and supported, electrical conducting means threading through the tubes for linking the current flowing through the conductor with the flux in said tubes.

11. Means for sending or receiving compressional waves comprising a plurality of magnetostrictive tubes arranged parallel with each other flexible coupling section means dividing said magnetostrictive tubes into sections independent of one another forming independent resonating elements, said coupling sections being short compared to the lengths of tubes coupled together, a pair of end plates one at each end of said tubes in which said tubes are positioned and supported, electrical conducting means threading through the tubes for linking the current flowing through the conductor with the flux in said tubes, means forming a liquid-tight chamber over the ends of the tubes with-said end plates and enclosing means surrounding the tubes. externally permitting a radiating medium to fill the space between the outer sides of the tube and said enclosing means.

12. Means for sending and receiving compressional waves comp-rising a plurality of parallelly arranged magnetostrictive tubes having spaced flexible coupling sections comprising. an outwardly flanged portion of the walls at an angle with the walls of the tubes, said sections being made to have a mechanical resonance at the same frequency, said tubes being terminated in a section adjacent the flexible coupling sections and means supporting the ends of said tubes in said terminal sections whereby the end complete tube sections are free to vibrate at their own natural frequency.

13. Means for sending and receiving compressional waves comprising a plurality of parallelly arranged magnetostrlctive tubes having spaced flexible coupling sections comprising an outwardly flanged portion of the walls at an angle with thewalls of the tubes, said sections being made to have a mechanical resonance at the same frequency, said tubes being terminated in a section adjacent the flexible coupling sections and means supporting the ends of said tubes in said terminal sections whereby the end complete tube sections are free to vibrate at their own natural frequency and means for inducing flux in a circulatory direction about said tubes for providing both transverse and longitudinal motion,

14. Means for sending and receiving compressional waves comprising a plurality of magnetostrictive tubes having spaced flexible coupling sections comprising an outwardly flanged portion of the walls at an angle with the walls of the tubes in chosen transverse direction, a pair of plates positioned at each end of the tubes for supporting said tubes, said tubes being arranged in said plates parallel to one another, forming a line of tubes and coil means threading through said tubes operatively associated with said tubes for sending and receiving compressional waves.

15. A device for sending and receiving compressional waves comprising a plurality of tubes, means enclosing and supporting said tubes at their ends sealing the inside of the tube from the propagating medium, conducting means threading the inside of the tubes through the end supporting means for impressing or linking magnetic flux circulating about the walls of the tubes, the outside of said tubes only being adapted to be exposed to the propagating medium.

- JOHN T. BEECI-ILYN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

